基于MSA法的高心墙堆石坝地震沉降易损性分析

多条带分析法(MSA)是新近提出的一种针对离散强度因子的易损性分析方法,为结构安全评估提供了有效路径,但目前在土石坝工程领域应用较少。本文针对高心墙堆石坝,选取坝顶震陷率为性能指标,建议了轻度、中度和重度破坏三个等级;考虑地震动的随机性,采用MSA法开展了易损性研究,得到了不同破坏等级的易损性曲线和概率,为大坝的强震性能评价提供准则和参考;不同条带数量下地震易损性分析结果表明,适当减少水平条带数量,对易损性结果影响不大,这有利于计算工况的减少。

Seismic subsidence fragility analysis of high CRFDs based on MSA

MSA is a fragility analysis method which is recently proposed and in view of discrete intensity factor, provides an effective approach for structural safety evaluation. However, this method is less applied in the field of earth-rockfill dams engineering. In this paper,crest settlement ratio is selected as the perfor-mance evaluation index in view of HCRFD, the seismic subsidence damage of HCRFDs was suggested di-viding in mild,moderate and severe damage three standards. Considering the uncertainty of earthquake,fra-gility analysis is carried out with MSA,and the fragility curves and probability corresponding different dam-age grades are acquired,which can provide criterion and reference for the dam evaluation under the strong earthquake. In addition, seismic fragility analysis results of different stripe numbers show that decreasing the number of horizontal stripe appropriately has little influence on the result of fragility,thus it is condu-cive to the reduction of calculation conditions.